When a patient is being examined via computed tomography, he/she is injected with a contrast agent via an injection system, denoted as injector below for short. The contrast agent serves the purpose of more effective visualization of the organ to be examined, which is transilluminated by X-rays in the computed tomograph. Images with the aid of which a doctor can undertake a diagnosis are generated via an imaging system from the X-ray signals acquired by a detector.
Both the X-radiation of the computed tomograph and the contrast agent injected via the injector impose a burden on the patient to be examined. Both the burden owing to X-radiation and the burden owing to the contrast agent must therefore be kept as light as possible. Consequently, it is normally only the mandatory quantity of contrast agent that is injected.
It is decisive here for the quality of imaging via the computed tomograph that the scanning operation of the computed tomograph be carried out at the correct instant. The correct instant is reached as a rule when the organ to be examined has been reached as desired by the injected contrast agent. In order to impose as little burden as possible on the patient, the radiation dose should be as light as possible, in addition.
DE 195 33 557 C1 discloses a method in which a suitable instant for the start of the scanning operation can be determined in a comparatively gentle way.
The level of the burden on the patient, and the quality of the images obtained are decisively codetermined also by the operating staff, who must operate the two devices, the computed tomograph, on the one hand and the injector, on the other hand, in a suitable way. Particularly in the case of the occurrence of malfunctions at one of the two devices, the experience and the reaction of the operating staff sometimes exerts considerable influence on the burden on the patient owing to the radiation or the contrast agent.
US 2001/0009994 A1 discloses an injector provided in particular for the application of a contrast agent. The injector can be connected via a data interface to an imaging system, in particular a computed tomograph, in order to enable data exchange between two devices or automated driving of the injector and/or the imaging system.
Likewise disclosed in the English language patent abstract JP 01207038 A is a computed tomograph that is connected via a data interface to an injector provided for the application of a contrast agent. Here, the injector is driven automatically by a control device of the computed tomograph. Further arrangements in the case of which a data exchange is performed between a computed tomograph and an injector are disclosed, for example, in US 2002/0165445 A1 or US 2002/0071521 A1.